Heavy rains + old pipes = raw sewage overflows

The heavy rains of the past months, even before the current storms, caused major overflows of raw sewage into Valley street and creeks. In total, 744,780 gallons of raw sewage escaped the collection system and entered protected surface waters over a two-month period.

The problem spots: 372,180 gallons released near Fetter Hot Springs; and 372,600 gallons near Verano Avenue to the Sonoma’s east side. None of the released raw sewage was recovered.

In total, 744,780 gallons of sewage escaped the collection system, according to a state Sanitary Sewer Overflow report. That total would fill about 37 in-ground swimming pools.

During times of heavy rain, the sewer collection and transmission pipes, both the lateral lines from private property and main trunk lines associated with the sewer sanitation plant on Eighth Street East, became overwhelmed. The raw sewage, mixed with rainwater, then escapes through manhole covers, eventually draining into Sonoma Valley’s primary creeks.

The fouled water is a health threat, according to Ron Prushko, Valley of the Moon Water District boardmember, particularly for kids playing in puddles. “The problem lies with a risk of disease removing footwear after this activity,” he said. “The risk is increased by the sewage overflows from manholes in the street.”

Parents and teachers should have children wash their hands thoroughly after removing footwear, Prushko advises. “This will help prevent serious disease.”

Dogs should be kept away from overflow areas as well.

Pipe repairs below Boyes Hot Springs on Hwy 12 to 6th Street are scheduled for repair, according to Barry Dugan of the Sonoma County Water Agency, operator of the sanitation plant, but not until 2018.

To help alleviate the overflow, Prushko said that property owners with downspouts connected to the Sonoma Valley sanitary sewer should redirect the path of rainwater to the street.

This water does not have raw sewage,” he said. “This would help prevent a disease outbreak in the community.”

An inspection program will begin this September to identify cracked and broken pipe segments on private property that connect to the main transmission pipes. Property owners will be required to pay for any repairs, but the sanitation district plans to offer a $1,000 credit towards that work.

The inspection and repair programs come after a settlement with the Regional Water Quality Control Board regarding a cease and desist order covering sanitary sewer overflows into surface waters.

The regional board has determined that a prohibition on new connections to the sewer collection system is not necessary at this time, but it has reserved the right to change its mind if conditions change in the future.

The question of whether and in what way large developments of housing or commercial hotels connected to the sewer system will contribute to the overflow problem is unknown at this point.

One hotel project has proposed the creation of sewage “holding tanks” operated to coincide smoothly with peak period use of the sewage transmission lines; this proposal is unusual and the question of jurisdiction over raw sewage entering the system is disputed.